Restoration process for porosity defects in high pressure die cast engine blocks

Abstract

A restoration process for restoring surface porosity defects in engine blocks cast using a high pressure die cast method. The areas of an engine block having surface porosity defects are identified and the areas not containing surface porosity defects are masked using an adhesive, reusable, rubberized mask. The masked surface is subsequently cleaned and a metal spray is applied to the surface porosity defects. The mask is removed and the restored surface porosity defects are hand finished to create an engine block having less than 0.05% surface porosity.

1. A restoration process for repairing surface porosity defects in high pressure die cast engine blocks resulting from the die casting process comprising the steps of: identifying an area in a surface containing at least one porosity defect resulting from the die casting process, the area defining a restoration area; masking an area adjacent to said restoration area with a mask; using a grit blasting process to clean the said restoration area; applying a metal spray to said restoration area; removing the mask from the area adjacent said restoration area; and finishing the restoration area. 
     
     
       2. The process of  claim 1 , wherein the step of masking an area adjacent said restoration area further comprises the step of masking the area adjacent to said restoration area with a reusable, adhesive backed, rubberized mask, having holes therein corresponding to the areas of restoration. 
     
     
       3. The process of  claim 1 , wherein the step of using a grit blasting process to clean the restoration area further comprises placing the masked engine block in a blasting cabinet; and the grit blasting process comprises an aluminum oxide grit blasting process. 
     
     
       4. The process of  claim 1 , wherein the step of applying a metal spray further comprises applying the spray with a spray gun containing a metal spray of the same type of metal as the surface metal. 
     
     
       5. The process of  claim 1 , wherein the step of finishing the restoration area further comprises manually finishing the restoration area with an abrasive finishing tool or an abrasive paper. 
     
     
       6. The process of  claim 1 , wherein said engine blocks are formed of an Aluminum Association alloy from the group consisting of: 360, 361, 364, 369, 380, 383, 384, 385, 390, 391, 392. 
     
     
       7. The process of  claim 1 , wherein said engine blocks are formed of Mercalloy XK360. 
     
     
       8. The process of  claim 1 , wherein the process further comprises a step of cutting holes in a mask, said holes corresponding to the size and shape of the porosity defect, after the step of identifying a restoration area and prior to the step of masking an area adjacent to said restoration area. 
     
     
       9. The process of  claim 1  wherein said engine block is cast utilizing a lost foam or sand cast process. 
     
     
       10. A restoration process for repairing surface porosity defects in high pressure die cast engine blocks after machining, the process comprising the steps of: identifying areas of restoration in a surface containing surface porosity defects, the defects being a result of the die casting process; masking areas in the surface not requiring restoration with a reusable, adhesive backed, rubberized mask, having holes therein corresponding to the areas of restoration; placing the masked engine block in a blasting cabinet; cleaning the areas of restoration exposed through the mask with an aluminum oxide grit blasting method to remove excess debris in the areas of restoration; applying a metal spray to the areas in a surface containing surface porosity defects, wherein the application is done manually with metal spray guns and the spray metal comprises an Aluminum-Silicon alloy having at least 4% Silicon by weight; removing the mask from the surface; and finishing the surface, wherein the finishing is done manually. 
     
     
       11. The process of  claim 10 , wherein said engine blocks are formed of an Aluminum Association alloy from the group consisting of: 360, 361, 364, 369, 380, 383, 384, 385, 390, 391, 392. 
     
     
       12. The process of  claim 10 , wherein said engine blocks are formed of Mercalloy XK360. 
     
     
       13. The process of  claim 10 , wherein the process further comprises a step of cutting holes in a mask, said holes corresponding to the size and shape of said porosity defect, after the step of identifying areas of restoration and prior to the step of masking areas not requiring restoration. 
     
     
       14. The process of  claim 10 , wherein said engine block is cast utilizing a lost foam or sand cast process.